In the electronic industry, fabrication of conductive line circuits is vital and inevitable. Traditionally, electroplating and etching processes accompanied by lithography technology are widely adopted in the printing circuit board (PCB) industry for manufacturing circuits. However, this method is not only time consuming but also very complicated, requiring many steps to construct even one layer of the circuit.
For these reasons, the development of convenient and fast processing techniques to fabricate conductive lines has attracted more and more attention in recent years. Using a printing process has several advantages such as selective deposition, repairability and re-printability. However, creating printed conductive lines with low resistivity and high current capacity creates a challenge. It would be advantageous to prepare printed conductive lines using polymer nanocomposites with low resistivity and high current carrying capacity.
No prior art appears to deal with a method to print conductive lines using polymer nanocomposites. Existing patents tend to deal with making printed lines through a different method or with the placement of conductive elements as the primary focus of the invention. One published patent application deals with using polymers to create a more conductive printed line. However, the method requires that a hole be formed on top of the polymer layer in order to remove the metallic substrate.
U.S. Pat. No. 5,039,824 for PRINTED CIRCUIT HAVING TWISTED CONDUCTOR LINES PRINTED THEREON issued Aug. 13, 1981 by Takashima et al. discloses a printed conductor including two twisted conductor lines each having a plurality of segments disposed alternately on opposite surfaces of a circuit board, the successive segments of each line being connected by electrically conductive elements passing through holes in the circuit board.
U.S. Pat. No. 4,604,298 for FINGER LINE SCREEN PRINTING METHOD AND APPARATUS issued Aug. 5, 1986 to Shevtchuk et al. discloses a method of screen printing using a conductive ink applied to a substrate to form a pattern of narrow, closely spaced conductive lines. Before screening, the conductive ink is exposed to ambient air until its viscosity is in the range 700,000 to 900,000 centipoise at 70° Fahrenheit.
United States Published Patent Application No. 2004/0035711 published Feb. 26, 2004 for METHOD OF MANUFACTURING PRINTED CIRCUIT BOARD AND MULTI-LAYERED PCB by Hyuek Jae Lee, et al. discloses a PCB fabrication method consisting of: plating a metal on a pattern-formed metallic substrate to form a conductive metal line; forming a polymer layer as a base substrate over the conductive metal line and drying the formed polymer layer; forming a via hole in the polymer layer, followed by plugging the via hole by electroplating; and removing the metallic substrate.
The patents and application listed above deal with methods of creating a printed circuit and the placement of the conductive elements, but do not focus on a method of making low resistivity printed conductive lines using polymer nanocomposites. No prior art has been found that focuses on creating printed lines and making them more conductive.
When performing the process of electroplating and etching lines on circuitry, a method of choice for printing conductive lines is one that reduces overall resistivity and improves current carrying capacity of the conductive lines.